As far as I know americans can play them as well, you just need a euro account, which is pretty easy to set up. Played a few tables last night and they were soft as hell. HEM dosnt work yet on them though.
No I never had that option, I had to open a Euro table click to buy in and pokerstars then gave me the option of converting dollars to euros, now I have the option at the cashier too. My cashier previously only displayed dollars.